Download Practicum_08

Biochemistry 451(01)
Monday 1:00-3:50PM, NSM C-339
November 24th and December 1st, 2008
Practicum Instructions
You may not receive any help from the instructor, laboratory assistant or your friends
during the practicum, so be prepared and ask any questions BEFORE coming to class.
When you receive your unknown compound you must:
(1)
Make up a solution of your unknown by weighing out 20 mg and dissolving it in 2 mL of
distilled water. Decide if it is an amino acid, carbohydrate or protein. Hint:
Molisch Test
Biuret Reagent*
Carbohydrate
Positive
Negative
Amino Acid
Negative
Negative
Protein
Negative
Positive
* To a test tube: add ten drops of unknown solution, followed by one “shot” of Biuret reagent,
vortex. Purple color indicates a positive test.
(2)
If it is a carbohydrate you must identify it by name and structure. Standards will NOT be
available in the laboratory so use your notes from the CHO lab. If there are reagents for
carbohydrate tests which are not available consider that a hint that you do not need to
perform those tests.
(3)
If it is an amino acid you must identify it by name and structure. You must do both TLC
and titration. Standards will be available in the laboratory.
(4)
If it is a protein you must determine its concentration, using Biuret reagent, by the
graphical method. Standards will be available in the laboratory.
Turn in a detailed laboratory report on Monday, December 8th, 2008.
GOOD LUCK!